Anisocytosis

Medical condition

Anisocytosis

Human red blood cells from a case of anisocytosis.

Anisocytosis is a medical term meaning that a patient's red blood cells are of unequal size. This is commonly found in anemia and other blood conditions. False diagnostic flagging may be triggered on a complete blood count by an elevated WBC count, agglutinated RBCs, RBC fragments, giant platelets or platelet clumps. In addition, it is a characteristic feature of bovine blood.

The red cell distribution width (RDW) is a measurement of anisocytosis^[1] and is calculated as a coefficient of variation of the distribution of RBC volumes divided by the mean corpuscular volume (MCV).

Types

Anisocytosis is identified by RDW and is classified according to the size of RBC measured by MCV. According to this, it can be divided into

Anisocytosis with microcytosis – Iron deficiency, sickle cell anemia
Anisocytosis with macrocytosis – Folate or vitamin B₁₂ deficiency, autoimmune hemolytic anemia, cytotoxic chemotherapy, chronic liver disease, myelodysplastic syndrome

Increased RDW is seen in iron deficiency anemia and decreased or normal in thalassemia major (Cooley's anemia), thalassemia intermedia

Anisocytosis with normal RBC size – Early iron, vit B12 or folate deficiency, dimorphic anemia, Sickle cell disease, chronic liver disease, myelodysplastic syndrome^[2]

Etymology

From Ancient Greek: an- without, or negative quality, iso- equal, cyt- cell, -osis condition.^[3]

References

^ Barbara J. Bain (2006). Blood cells: a practical guide. Wiley-Blackwell. pp. 66–. ISBN 978-1-4051-4265-6. Retrieved 10 November 2010.
^ Red Cell Distribution Width (RDW) at eMedicine
^ "Archived copy" (PDF). Archived from the original (PDF) on 2018-08-20. Retrieved 2018-05-19.{{cite web}}: CS1 maint: archived copy as title (link)

External links

Classification	D ICD-10: R71 ICD-9-CM: 790.09 DiseasesDB: 725

Blood film findings

Red blood cells

Size	Anisocytosis Macrocytosis Microcytosis
Shape	Poikilocytosis Membrane abnormalities Acanthocyte Codocyte Elliptocyte Hereditary elliptocytosis Spherocyte Hereditary spherocytosis Dacrocyte Echinocyte Schistocyte Degmacyte Sickle cell/drepanocyte Sickle cell disease Stomatocyte Hereditary stomatocytosis
Colour	Anisochromia Hypochromic anemia Polychromasia
Inclusion bodies	Developmental Howell–Jolly body Basophilic stippling Pappenheimer bodies Cabot rings Hemoglobin precipitation Heinz body
Other	Haemoconia Red cell agglutination Rouleaux

White blood cells

Lymphocytes	Reactive lymphocyte Smudge cell Russell bodies
Granulocytes	Hypersegmented neutrophil Arneth count Pelger–Huët anomaly Döhle bodies Toxic granulation Toxic vacuolation Critical green inclusion Alder–Reilly anomaly Jordans' anomaly Left shift
Other	Auer rod